Transplant candidates should undergo an assessment of their mental health, social support, lifestyle and behaviours. The primary aims of this 'psychosocial evaluation' are to ensure transplantation is of benefit to life expectancy and quality of life, and to allow optimisation of the candidate and transplant outcomes. The content of psychosocial evaluations is informed by evidence regarding pretransplant psychosocial predictors of transplant outcomes. This review summarises the current literature on pretransplant psychosocial predictors of transplant outcomes across differing solid-organ transplants, and discusses the limitations of existing research. Pretransplant depression, substance misuse, and nonadherence are associated with poorer post-transplant outcomes. Depression, smoking and high levels of prescription opioid use are associated with reduced post-transplant survival. Pretransplant nonadherence is associated with post-transplant rejection, and nonadherence may mediate the effects of other psychosocial variables such as substance misuse. There is evidence to suggest social support is associated with likelihood of substance misuse relapse after transplantation but there is a lack of consistent evidence for an association between social support and post-transplant adherence, rejection or survival across all organ transplant types. Psychosocial evaluations should be undertaken by a trained individual and should comprise multiple consultations with the transplant candidate, family members, and healthcare professionals. Tools exist which can be useful for guiding and standardising assessment, but research is needed to determine how well scores predict post-transplant outcomes. Few studies have evaluated interventions designed to improve psychosocial functioning specifically pretransplant. We highlight the challenges of carrying out such research and make recommendations regarding future work.